How would you validate a checkbox in ASP.Net MVC 2?

Question

Using MVC2, I have a simple ViewModel that contains a bool field that is rendered on the view as a checkbox. I would like to validate that the user checked the box. The [R

Answer 1

I usually use:

[RegularExpression("true")]

Answer 2

I too am looking for a way to have the model binder correctly handle check boxes with Boolean values. In the mean time I'm using this in the Actions:

Object.Property = !String.IsNullOrEmpty(Request.Form["NAME"]);

Maybe this will be of some use to you.

Answer 3

If you didn't want to create your own custom validator and still wanted to use existing attributes in the model you could use:

[Range(typeof(bool), "true", "true", ErrorMessage="You must accept the terms and conditions.")]

This ensures that the range of the boolean value is between true and true. However, whilst this method will work, I would still prefer to use a custom validator in this scenario. I just thought i'd mention this as an alternative option.

Answer 4

a custom validator is the way to go. I'll post my code which I used to validate that the user accepts the terms ...

public class BooleanRequiredToBeTrueAttribute : RequiredAttribute
{
    public override bool IsValid(object value)
    {
        return value != null && (bool)value;
    }
}